1. Technical Field
Embodiments of the present disclosure relate generally to integrated circuits (IC), and more specifically to an input-output (I/O) circuit supporting multiple I/O logic-level swings.
2. Related Art
Input-output (I/O) circuits are generally employed in integrated circuits (IC) to transmit signals via pins of an IC to components external to the IC, and to receive signals via pins of the IC from components external to the IC.
With respect to digital signals, I/O logic-level swing refers to the voltage difference between logic high and logic low levels of outputs of (and inputs to) the I/O circuit. For example, if an output signal of an I/O circuit has a logic high voltage of five volts (5V) and a logic low voltage of 0V, the logic-level swing of the output signal is 0V to 5V. Similarly, if an input signal to the I/O circuit has a logic high voltage of 5V and a logic low voltage of 0V, the logic-level swing of the input signal is 0V to 5V. In general, the I/O logic-level swing supported by the I/O circuit is 0V-5V.
An I/O circuit may need to support multiple I/O logic-level swings. Thus, the I/O circuit may need to be programmable to generate an output signal with one of multiple logic-level swings, such as, for example, 0V-5V and 0V-3.3V. Similarly, the I/O circuit may need to support reception of an input signal with one of multiple logic-level swings.